A marine positioning system can have a floating platform, an external vessel, a positioning module, and a control module. The external vessel can be configured to selectively tow and maintain the floating platforming in a preselected position. The external vessel can have a propulsion unit. The propulsion unit can be configured to propel the floating platform in a preselected direction between 0 and 360 degrees. The control module can be in communication with the propulsion unit and the positioning module. The control module can be configured to receive the location data from the positioning module. Also, the control module can be configured to determine if the floating platform is in the preselecting position. In addition, the control module can be configured to generate instructions including the preselected direction that the floating platform needs to travel to be positioned in the preselected position.

An illustrative method for CO2 sequestration may include the step of sequestering at least a portion of a CO2 gas emitted during operation of the ready-mix concrete production system in (i) a ready-mix concrete produced by the read-mix concrete production system, and/or (ii) calcium carbonate formed by processing water used during operation of the ready-mix concrete production and delivery system.

A slide-in structural interface between a Sea Water Intake Riser (SWIR) and a floating unit hull or sump tank bottom plate permits a pull-in, diver-less installation of the SWIR. Certain embodiments include an integrated, easily maintainable strainer.

This invention provides a means of loading, processing and conditioning raw production gas, production of CGL, storage, transport, and delivery of pipeline quality natural gas or fractionated products to market. The CGL transport vessel utilizes a pipe based containment system to hold more densely packed constituents of natural gas held within a light hydrocarbon solvent than it is possible to attain for natural gas alone under such conditions. The containment system is supported by process systems for loading and transporting the natural gas as a liquid and unloading the CGL from the containment system and then offloading it in the gaseous state. The system can also be utilized for the selective storage and transport of NGLs to provide a total service package for the movement of natural gas and associated gas production. The mode of storage is suited for both marine and land transportation and configured in modular form to suit a particular application and/or scale of operation.

CO.sub.2 in the liquid or super-critical state is delivered by at least one carrier vessel from at least one CO.sub.2 storage site, which may be an onshore site, to an integrated offshore facility. The integrated offshore facility is provided with at least one on-site storage tank or vessel adapted to store CO.sub.2 in the liquid or super-critical state and with equipment for marine transfer of CO.sub.2 in the liquid or super-critical state. CO.sub.2 is utilised as required from said at least one on-site storage tank or vessel for EOR at said offshore site or for EGR at said offshore site by injection into a sub-sea oil or natural gas bearing reservoir and recovery of oil and/or natural gas from a resulting production stream.

There is disclosed a near shore floating vessel for large scale production of methanol (capable of producing at least 4000 tons per 24-hour day) from natural gas (methane) and for export shipment. More specifically, the near shore floating vessel obtains methane from an on-shore methane stream or pipeline. The disclosed near-shore floating vessel provides several environmental and commercial advantages to move methane export to a near shore instead of an on-shore location.

A first permissible operating range of the self-elevating vessel is determined based on a first structural analysis of the self-elevating vessel under a first set of conditions. A structural utilization ratio of the self-elevating vessel is determined based on a second structural analysis of the self-elevating vessel under first and second sets of conditions. Safety of lowering the self-elevating vessel from an elevated state to a first hull draft level is determined when the structural utilization ratio is less than a predetermined value. Safety of lowering the self-elevating vessel from the first hull draft level to a second hull draft level is indicated when positional displacement data obtained while the vessel is at the first hull draft level indicates that the positional displacement of the self-elevating vessel while at the first hull draft level is within the first permissible operating range.

CO.sub.2 in the liquid or super-critical state is delivered by at least one carrier vessel from at least one CO.sub.2 storage site, which may be an onshore site, to an integrated offshore facility. The integrated offshore facility is provided with at least one on-site storage tank or vessel adapted to store CO.sub.2 in the liquid or super-critical state and with equipment for marine transfer of CO.sub.2 in the liquid or super-critical state. CO.sub.2 is utilised as required from said at least one on-site storage tank or vessel for EOR at said offshore site or for EGR at said offshore site by injection into a sub-sea oil or natural gas bearing reservoir and recovery of oil and/or natural gas from a resulting production stream.

An offshore LNG processing plant includes a first module including a personnel accommodation facility on a first vessel, a second module including a gas treatment facility on a second vessel, and a third module including a gas liquefaction facility on a third vessel. Each of the first, second, and third modules are assembled on the corresponding vessels, and then transported to an offshore location in a body of water, such as a river, a lake, or a sea. At the offshore location, each vessel deploys legs to the bed of the body of water to raise a hull of each vessel out of the water. The first module is then coupled to the second module, and the second module is coupled to the third module. A fourth module on a fourth vessel is coupled to the third module to provide LNG storage.

A buoyant structure having a hull, a main deck, an upper cylindrical side section extending downwardly from the main deck, an upper frustoconical side section, a cylindrical neck, a lower ellipsoidal section that extends from the cylindrical neck, an ellipsoidal keel and a fin-shaped appendage secured to a lower and an outer portion of the exterior of the ellipsoid keel. The upper frustoconical side section located below the upper cylindrical side section and maintained to be above a water line for a transport depth and partially below the water line for an operational depth of the buoyant structure.